This invention relates to the use of an element status indicator for a ceramic glass cook top.
Conventional ceramic glass cook tops generally employ either a dark red or brown ceramic glass top. With red coloured ceramic glass only red light will be permitted to pass. This has meant that in conventional cook tops generally red neon lamps have been used underneath the sheet of glass as indicators for a number of conditions.
In particular it has proven useful to provide indication of whether it is safe to touch the surface of the cook top. The generally accepted xe2x80x9csafexe2x80x9d temperature is approximately 50-60xc2x0 C., above which any such indicator would be lit. In some cases however because all the indicators (for various different conditions eg: dual element) will be red it can be somewhat confusing as to what each indication relates to at a quick glance. In the worst case this may lead to inadvertently placing ones hand or other inappropriate objects onto the cook top when it is hot.
It is an object of the present invention to provide an element status indicator for a ceramic glass cook top which goes some way to overcoming the abovementioned disadvantages or at least provides the public with a useful choice.
In a first aspect the present invention may broadly be said to consist in a cooktop including at least one heating means beneath a substantially colourless and transparent ceramic glass surface with an opaque layer on sections of the underside thereof and a status indicator, said status indicator comprising:
indication means positioned directly underneath and proximate to said surface wherein said opaque layer is not present directly above said indication means, allowing said indication means to be visible directly above said cook top, and
a control means configured to determine the temperature of said surface above said heating means and energise said indication means when said surface above said heating means is above a predetermined temperature and de-energises said indication means when said surface above said heating means is below said predetermined temperature.
Preferably said control means comprises an electric circuit fed from a transformer less supply.
Preferably the colour emitted by said indication means is dependent on whether said heating means is energised.
Preferably said indication means is at least one light emitting diode.
Preferably said control means includes heat sensing means positioned in close proximity to said heating means, the electrical characteristics of which are temperature dependent.
Preferable said heat sensing means is a bimetallic switch.
Alternatively said heating sensing means is a thermistor.
In a further alternative said heating sensing means is a positive temperature coefficient paste coated on the underside of said surface or said opaque layer.
Preferably said predetermined temperature is the maximum temperature for which human skin can safely be exposed to.
Preferably said maximum temperature is 50xc2x0 C.
To those skilled in the art to which the invention relates, many changes in construction and widely differing embodiments and applications of the invention will suggest themselves without departing from the scope of the invention as defined in the appended claims. The disclosures and the descriptions herein are purely illustrative and are not intended to be in any sense limiting.